From: Robert v. D. <rob...@an...> - 2009-04-23 11:37:52
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Hello Christian and Simone, Actually it all worked out-of-the-box. I used the description on this page: http://geoserver.org/display/GEOSDOC/Using+the+ImageMosaic+JDBC+Plugin to setup the JDBC connection to Oracle, create the metadata scripts and load some sample geotiffs using the mosaicjdbc jar. The only difficulty I had was that Oracle uppercases it's tablenames when you query them, so you need them uppercased in gdal commands as well :) Now it's upto my cliënt to agree with this approach instead of using actual Georasters and see what the performance is when we load the entire dataset this way. Thanks for the help, it's much appreciated! Robert. Christian Müller wrote: > To answer the questions > 1) Performance > I am handling 3 maps with about 8 million tiles , biggest map 4 > million tiles , biggest layer consists of 2 million tiles. > The tiles are stored in png format. (Compression). Tile sizes are > 256x256 and 512x512. > The decoding (Decompression) of the tiles is done in a multithreaded > manner. Multiple/Multicore CPUs will be used if present. > The db lookup to find the right tiles is very fast if you have the > proper indexes. Decoding starts when the first tile is fetched, > fetching and decoding works like streaming using a queue from the > java.concurrent package. > Store your tiles as single banded images with a color table. Check > with gdalinfo, if you have multiple bands use gdal_merge > with the -pct option to produce a big picture. Afterwards apply > gdal_retile. > You can import the output of gdal_retile. > Performance decreases when doing a request with a different CRS, > because the whole picture has to be transformed. You will get see a > WARNING in the log file. Try to avoid it. > Environment: Geoserver running on Linux PPC using DB2 Spatial Extender > on an AIX Box > 2) > If you have to use Oracle Georaster. I agree to Simone. The best would > be to implement a special coverage store. > 3) At the moment, the plugin is not able to handle rotated or skewed > images, but if necessary, I would add this feature. > > christian > > -- ------------------------------------------------------- BEng. R.J.M. van Drunen Anargistic Owner - Software Engineer Sint Luciaplein 27 5211 ZR 's-Hertogenbosch mob: +31 062369319 http://www.anargistic.nl http://www.linkedin.com/in/robertvandrunen ------------------------------------------------------- |